1. Field of the Invention
The present invention concerns a device for simultaneously rotating a payload relative to a structure and supporting the payload (and therefore guiding its rotation).
The invention concerns a device of this type, also known as a "rotation drive table", which can be used in diverse applications, in particular in a satellite antenna pointing mechanism.
In this type of application the antenna beam can be oriented by rotating the parabolic reflector about its focal point.
2. Description of the prior art
To this end, until now either the reflector has been attached to a universal joint structure centered on the focal point by an arm and the universal joint has been motorized or the concept explained in the document FR-A-2 646 023 has been used.
In either case, the drive units must combine great stiffness, high angular resolution, compact overall dimensions and a high drive torque.
There has not previously existed any mechanism combining all these qualities and capable of driving a high inertia load (typically in the order of 200 kg.m.sup.2) with a sufficient natural frequency.
These problems also arise in many other applications such as pointing a telescope or driving robot arms.
An object of the invention is to propose a support and drive device which meets these various requirements and which can be used not only in the applications just mentioned but also in all fields where the aforementioned qualities are found to be advantageous.